Misfire

2013 FIAT 500
106,000 MILES • 4 CYL • 2WD • MANUAL
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DIVIDES
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Bought it with a misfire.. had an extra set of new coils so i installed them still firing on cylinder 3. It had codes misfire on all but now i got it down to 1, cylinder 3. Changed the plug from 3 to 4, still same code, even though the plug in 3 looked different than 4 for some reason. It also had some fuel on it, on number 3. Is it common to have bad injectors on these cars? I also heard that a bad VVT for that cylinder could also cause same thing. Car runs rough. If you hit it hard it smokes black from all the unburned gas.
Jun 7, 2021 at 4:41 PM
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DIVIDES
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runs better with the new coil, doesn't stall, but still not right.. can I test these with the light tester used at the injector harness?
Jun 8, 2021 at 2:34 PM
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BORIS K
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Hello,

Is the engine fitted with the multi air system? If yes first scan the PCM for codes. Next check oil level and oil quality. When was the engine oil replaced? Was the correct grade used? The multi air system work on hydraulic pressure to operate the intake valves and is very sensitive to low oil or poor oil quality.

How the system works:

https://youtu.be/Td9Gz_h7Qpg

Please let us know how you get along.

Cheers, Boris
Jun 9, 2021 at 6:21 AM
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DIVIDES
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Hmmm, didn't know that. Will 5w-30 work? I can change it today.
Jun 9, 2021 at 6:24 AM
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DIVIDES
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These pulled up mot sure if they are related. I deleted them and they went away.
Jun 9, 2021 at 6:33 AM
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DIVIDES
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Also, i got the quick lit tool and i touched all injector bodies and all firing correctly.
Jun 9, 2021 at 9:53 AM
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DIVIDES
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Also swapped spark plugs and coils into another cylinder and tested for spark with the light and its there.
Jun 9, 2021 at 10:19 AM
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DIVIDES
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How do i remove the VVT on this cylinder, don't see bolts. Changed the oil and it has gotten better. I think the VVT maybe dirty.
Jun 9, 2021 at 10:28 AM
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DIVIDES
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If i delete the code it gets a bit better, still 303 and sometimes 353 ignition coil.
Jun 9, 2021 at 10:31 AM
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DIVIDES
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Compression 130 on cylinder 2 and 35 on cylinder 3, i guess it's shot.
Jun 9, 2021 at 1:50 PM
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JACOBANDNICKOLAS
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Hi,

Did you check the compression both wet and dry? That is to determine if it is a ring issue or a valve/head gasket issue. Based on the mileage, I have a feeling it could be a gasket issue.

Here is a link that explains how to test compression. Do it both dry and wet. Well, you already did it dry. Add about a tablespoon full of oil to cylinder 3 and recheck compression and let me know the results.

https://www.2carpros.com/articles/how-to-test-engine-compression

Take care,

Joe



Jun 12, 2021 at 10:15 PM
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DIVIDES
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Just dry compression, removed fuel pump relay, removed plugs from cylinders 2 and 3, one was great the other was low. i added a tablespoon but didn't measure after it, though it may bring it back up, but it's still misfiring. Am going to sell it like it is, not worth replacing either. Thanks for all the help.
Jun 13, 2021 at 6:09 AM
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JACOBANDNICKOLAS
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Hi,

You are very welcome. Please feel free to come back any time in the future if you have questions.

Take care of yourself,

Joe
Jun 13, 2021 at 6:35 PM